A 2-day shutdown of the 405 Freeway could lead to massive traffic jams. Or not.

It's happening again. Los Angeles residents are stocking up on groceries, putting their cars in their garages and preparing for a weekend at home as the city looks ahead to this weekend's anticipated and dreaded "Carmageddon 2." Or are they?

Like last year's first Carmageddon, a 10-mile stretch of the normally gridlocked Interstate 405 will be shut down this weekend. This time, the closure will enable crews to demolish part of the Mulholland Drive Bridge. I-405 is the most heavily trafficked road in the country.

But unlike last year, the lead-up to Carmageddon 2 has not been accompanied by near-apocalyptic warnings about traffic jams and nightmare delays. Why? Because last year's Carmageddon went so smoothly that it barely made a blip in the city's activities. "People stayed home and had a relaxing weekend instead of driving all over town," Morgan Wyenn, an attorney on the NRDC's L.A.-area Air Quality Project, wrote on the Switchboard blog. "Those brave enough to leave home stayed in their neighborhoods, enjoying local restaurants and parks."

Instead of issuing warnings, Los Angeles is trying a different tactic this year: requesting that people be neighborly.

"Threats that it's going to be bumper to bumper are going to be taken as empty threats: people experienced what happened last time and saw that wasn't the case," Martin Wachs, a senior researcher at the RAND Corporation, told the New York Times.

The city is offering a wide range of incentives for the 500,000 motorists who normally travel the 405 every weekend to try something different. Los Angelinos can take advantage of discounts to local restaurants, theaters and museums, which will keep them closer to home and also benefit the local economy. There are also discounts for people who take the train.

There's even a Twitter hashtag, #405things, for people looking for ideas of weekend activities.

One area of traffic remains a concern this year: helicopters. So many TV news choppers hovered above the 405 for hours at a time last year that many residents complained about the non-stop noise. L.A. has responded by asking pilots to fly higher this year and to not hover over peoples' homes, although no specific guidelines have been issued, according to the Los Angeles Times.

This year's Carmageddon begins at 7 p.m. Friday night and is expected to last until 5 a.m. Monday morning. Last year, the roads opened 17 hours ahead of schedule, but this year's job is much bigger and is expected to require the entire weekend.